I can use the "move page" action to move a page underneath the "Variants" node - I can't drag a page onto the "Variants" node, though (which is fine). On the other hand, I can drag it below or above any existing page variants underneath that node.
The result is pretty much undefined - I didn't get any exceptions or errors, but I could continue to add sub pages to such a page (not page variant) node; on the other hand, I can't choose an audience for it.
You should not be able to move a page, using any means:
- inside the Variants node
- above, below or "inside" any page variant
In the "move page" dialog, the corresponding move buttons could be either disabled, if the selected target doesn't allow the move operation to take place, or elements I can't move to could be hidden from the tree entirely (probably preferred).